Effects of low-frequency electromagnetic field on the surface quality of 7050 aluminum alloy ingots during the hot-top casting process

Xiang-jie Wang, Jian-zhong Cui, Yu-bo Zuo, Zhi-hao Zhao, and Hai-tao Zhang Key Lab of Electromagnetic Processing of Materials (Ministry of Education), Northeastern University, Shenyang 110004, China

摘 要：To improve the quality of 7050 aluminum alloy ingots, low-frequency electromagnetic （LFE） field was applied during the conventional hot-top casting process. Macrostructures and microstructures of the ingots by the conventional and LFE hot-top casting processes were studied. The experimental results show that when the LFE field is turn off during the hot-top casting process, cold folding appears, and the as-cast structure becomes very coarse. Additionally, the thickness of the shell zone is much thinner during the low-frequency electromagnetic hot-top casting process than that during the conventional hot-top casting process. Some reasons for low-frequency electromagnetic field improving the surface quality, refining the structure of the ingot, and minimizing the thickness of the shell zone have been studied.

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